Wall covering



FIG. 1 is a front view of a wall covering showing my design;

FIG. 2 is a top view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right view thereof;

FIG. 6 is a back view thereof; and,

FIG. 7 is a bottom, right perspective view thereof.

CLAIM The ornamental design for a wall covering, as shown and described.